This invention relates to an apparatus and a method for regenerating an adsorbent such as active carbon and zeolite by heating.
In order to eliminate organic matter, for example dodecylbenzensulfonate and phenol, from industrial waste water, an adsorbent which adsorbs them is used. To the end of reclaiming the adsorbent which has adsorbed the matter and water, it is necessary to eliminate the adsorbed matter and water from the adsorbent by heating the adsorbent. The temperature required for eliminating the water content from the adsorbent is 100.degree. C., whereas the temperature required for desorbing the adsorbed matters from the adsorbent is 600.degree. C. to 800.degree. C.
Japanese Patent Application Public-disclosure No. 86495/1975 discloses a method and an apparatus for regenerating an adsorbent wherein the drying of the adsorbent and the regeneration thereof are individually executed. In the method and apparatus, however, furnaces for the respective steps are installed in a manner to be long in the horizontal direction, and the adsorbent having entered the drying furnace is heated while flowing horizontally, so that inevitably the adsorbent and water vapor generated therefrom flow in the same direction. This leads to the disadvantage that the dried adsorbent scatters in the horizontal direction together with the water vapor. Likewise, in the regenerating furnace which is long in the horizontal direction, the adsorbent scatters in the horizontal direction along with desorbed gases.
Japanese Patent Application Public-disclosure No. 45693/1976 discloses a method and an apparatus for regenerating an adsorbent wherein the adsorbent is dried and regenerated by directly heating it with a high-temperature gas. In the case of performing the drying and the regeneration by the direct heating, there are such disadvantages that part of the surface of the adsorbent is brought to a high temperature by the high-temperature gas, so the adsorbent itself burns, and that the adsorbent from which adsorbed matter has been eliminated adsorbs impurities in the high-temperature gas, so the purity of the adsorbent lowers. Further, according to the cited reference, the drying and the regeneration are executed in the course in which the adsorbent is caused to descend vertically. This leads to the disadvantage that the desorbed gases ascending are adsorbed to the adsorbent again within a furnace, so the adsorption performance of the adsorbent is degraded.